Abstract

Phenytoin is known to be able to induce cerebellar atrophy in patients with epilepsy. It is also known that a CYP2C9 mutation (*2 or *3) reduces phenytoin metabolism by 25–50% and can increase the risk of phenytoin-related side effects. We examined the influence of CYP2C9 polymorphisms on total cerebellar volume and cerebellar gray and white matter volumes in patients with epilepsy taking phenytoin.